Recently a friend (we'll call him "Bob") signed up for a dating site called OK Cupid. As he was filling out the form listing his interests, wants, dreams, desires, etc, OK Cupid asked if he wanted to populate that form using Facebook Connect. Bob clicked yes and didn't think twice about it. A few days later he happened to check his Facebook apps page, whereupon he found one called OK Cupid, which was set by default to publish "one line stories" of his recent Cupid activity on his wall.

When you agree to use Facebook Connect, OK Cupid does not alert you it is installing a Facebook app, though it does display a splash screen that says it will publish content to your wall. Still, Bob was a bit taken aback. Fortunately for him, it was no big deal -- he just uninstalled the app. Of course, it would have been a different story if Bob a) was married, b) had signed up for OK Cupid on the QT, and c) his spouse saw some of his updates on Facebook. You can fill in what happens after that. (Click on the screen cap below for a closer look at what to watch out for.)

What's cool is that not only does the ACLU test your knowledge of how much information Facebook quizzes and other apps can mine from your profile (i.e., nearly everything), it also does a little data scraping of its own to display exactly the kinds of data every app can access about your friends merely by installing it.

That includes: photos, status updates, political affiliations, birthdays, hometowns, etc. In other words, stuff you might feel comfortable sharing only with your Facebook friends is also being shared whenever you or your friends install a quiz asking what kind of flower/ninja/vampire you are. (Click on the screen for a closer look.)